谷歌的“go”和范围/职能
在 golang.org 给出的示例服务器之一中：
package main
import (
"flag"
"http"
"io"
"log"
"template"
)
var addr = flag.String("addr", ":1718", "http service address") // Q=17, R=18
var fmap = template.FormatterMap{
"html": template.HTMLFormatter,
"url+html": UrlHtmlFormatter,
}
var templ = template.MustParse(templateStr, fmap)
func main() {
flag.Parse()
http.Handle("/", http.HandlerFunc(QR))
err := http.ListenAndServe(*addr, nil)
if err != nil {
log.Exit("ListenAndServe:", err)
}
}
func QR(c *http.Conn, req *http.Request) {
templ.Execute(req.FormValue("s"), c)
}
func UrlHtmlFormatter(w io.Writer, v interface{}, fmt string) {
template.HTMLEscape(w, []byte(http.URLEscape(v.(string))))
}
const templateStr = `
<html>
<head>
<title>QR Link Generator</title>
</head>
<body>
{.section @}
<img src="http://chart.apis.google.com/chart?chs=300x300&cht=qr&choe=UTF- 8&chl={@|url+html}"
/>
<br>
{@|html}
<br>
<br>
{.end}
<form action="/" name=f method="GET"><input maxLength=1024 size=70
name=s value="" title="Text to QR Encode"><input type=submit
value="Show QR" name=qr>
</form>
</body>
</html>
`
为什么 template.HTMLEscape(w, []byte(http.URLEscape(v.(string)))) 包含在 UrlHtmlFormatter< 中/代码>?为什么不能直接链接到"url+html"？
另外，如何更改 func QR 以接受参数值？我想要它做的是接受一个命令行标志来代替 req *http.Request ...提前致谢...
In one of the example servers given at golang.org:
package main
import (
"flag"
"http"
"io"
"log"
"template"
)
var addr = flag.String("addr", ":1718", "http service address") // Q=17, R=18
var fmap = template.FormatterMap{
"html": template.HTMLFormatter,
"url+html": UrlHtmlFormatter,
}
var templ = template.MustParse(templateStr, fmap)
func main() {
flag.Parse()
http.Handle("/", http.HandlerFunc(QR))
err := http.ListenAndServe(*addr, nil)
if err != nil {
log.Exit("ListenAndServe:", err)
}
}
func QR(c *http.Conn, req *http.Request) {
templ.Execute(req.FormValue("s"), c)
}
func UrlHtmlFormatter(w io.Writer, v interface{}, fmt string) {
template.HTMLEscape(w, []byte(http.URLEscape(v.(string))))
}
const templateStr = `
<html>
<head>
<title>QR Link Generator</title>
</head>
<body>
{.section @}
<img src="http://chart.apis.google.com/chart?chs=300x300&cht=qr&choe=UTF- 8&chl={@|url+html}"
/>
<br>
{@|html}
<br>
<br>
{.end}
<form action="/" name=f method="GET"><input maxLength=1024 size=70
name=s value="" title="Text to QR Encode"><input type=submit
value="Show QR" name=qr>
</form>
</body>
</html>
`
Why is template.HTMLEscape(w, []byte(http.URLEscape(v.(string)))) contained within UrlHtmlFormatter? Why can't it be directly linked to "url+html"?
Also, how could I change func QR to accept parameter values? What I'd like for it to do is accept a command-line flag in place of req *http.Request ... Thanks in advance...
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函数
template.HTMLEscape的签名为：template.FormatterMap的类型声明为：因此，
FormatterMap映射元素值函数的签名是：UrlHtmlFormatter函数是一个包装器，为HTMLEscape函数提供FormatterMap映射元素值函数签名。The signature for function
template.HTMLEscapeis:The type declaration for
template.FormatterMapis:Therefore, the signature for a
FormatterMapmap element value function is:The
UrlHtmlFormatterfunction is a wrapper to give theHTMLEscapefunction theFormatterMapmap element value function signature.